This process demonstrates how to lay a basic precast paving stone walkway or patio.
For large projects, it's important to consult a soils engineer to
evaluate whether your soil is prone to abnormal expansion and
contraction due to water holding capacity. The most problematic is
clay, and to compensate for its plasticity, you may need to lay thicker
base material or add a geo-textile layer.
1. Prepare siteRemove all
existing plants, lawn and constructed elements down to the level of
undisturbed soil. Excavate down to the depth dictated by the design
plan for the project. This is calculated as finish grade less the depth
of paver, sand, and gravel layers. Excavation can range from just 6"
for walkways and patios to as much as 18" for driveways.
2. Compact subgradeThis
step ensures that the exposed soil is compacted to at least 95% or
higher if the surface is to accommodate vehicular traffic. This is
doubly important where the building pad is elevated or composed of cut
and fill because there can be loose layers deeper down that can settle
later on causing a depression in your paving. Special power equipment
is necessary to achieve this compaction rate in heavy soils.
3. Lay geotextileThis is
special fabric designed to help prevent deep soil disturbance due to
freeze-thaw or over saturation. It is not necessary on all projects,
but provides greater insurance against unexpected changes in subgrade.
4. Spread base materialThe
average residential project for pedestrian use is a 4 to 6 inch deep
layer of gravel, but this can vary considerably from one project
location to the next. Above this may be a two inch layer of coarse sand
or very fine gravel that provides the setting bed for pavers.
5. Edge restraintsThese
products made of flexible PVC are designed to hold the base material
layer in place so it does not erode away and allow the outside pavers to
tip. Staked into place, it is an essential product that provides the
most cost effective way of keeping a paving stone patio as crisp as the
day it was built. Larger heavier restraints will be required for
driveways to accommodate the weight of vehicles. Some projects may
require more elaborate concrete or edge paver installation.
6. Bedding sandThis layer
of concrete sand is spread no thicker than 1.5 inches. It is screeded
to create a perfectly level base for the pavers. This step requires
attention to detail ensuring the entire paved surface is perfectly
leveled. the preference is for more
expensive polymeric sand, which is valued for preventing ants from
tunneling through joints and creating mounds on the surface. It's also
better for resisting weeds. Due to the local availability of finely
crushed local granite, this provides a lower cost ant-resistant
alternative due to the sharp edges.
7. Lay paversString lines
or chalk lines may be required to install the pavers. Spacing may be
dictated by spacer bars formed into each paver, otherwise a gap of 1/16"
to 3/16" is required between each paver. When the pattern results in
irregular gaps at the final edges of a vehicular surface, it is a rule
of thumb not to cut pavers to sizes any smaller than one third of a
whole paver.
8. Sand and sweepUse dry
joint sand to spread over the finished paving and sweep it into the gaps
between pavers, then compact the entire surface to work it in deeper
and add more sand until joints are adequately filled For large projects,
a mechanical device may be used to speed the process and provide
additional compaction, particularly for vehicular surfaces.
9. Seal paversA penetrating
acrylic sealer with a mat surface is recommended to keep paver color
from fading and to prevent stains. It will require reapplication in the
future to maintain the beauty of the paving, particularly in areas with
snow, hard water or surfaces for vehicles.
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